This book is primarily about bearingless machines, where the magnetic levitation of the rotor is provided from within the main stator bore (in addition to torque production if motoring, or electrical power production if generating). The bearingless type of motor is still, to some extent, in the development stage and therefore still at an early point of evolution.

The basic theory, design and control rules are being researched and investigated and there is still much work to be done. The authors have had many years of experience in the design and operation of bearingless machines and this book represents their combined experience as pioneers in this area. Therefore this book describes the leading edge of the technology as it stands today.